Why is it
With the exception of projects where louvres are specified purely to provide vision screening, their effectiveness in letting the air in and out of a building will always be a critical performance consideration.
Aerodynamic Coefficient gives you that critical performance information to make sure the louvre offers the right amount of air.
What is Louvre
A unitless number, determined by airflow testing, representing the aerodynamic effectiveness of the louvre.
Unlike % Free Area, it accounts for the design and configuration of the louvre and provides an accurate measure of its airflow performance.
In testing, values are recorded for both air intake and exhaust and typically range from 0.1 to 0.5 (the higher the number, the more efficient the airflow).
Performance
EN 13030:2001 converts the Aerodynamic Coefficient to an Airflow Class rating between 1 and 4. The lower the class the better the airflow performance.
| Class | Discharge Loss Coefficient | Rating |
|---|---|---|
| 1 | 0.4 to 1 | Excellent |
| 2 | 0.3 to 0.399 | Very Good |
| 3 | 0.2 to 0.299 | Good |
| 4 | 0.199 & below | Fair |
This is generally combined with the rain defence classification or Penetration Class rated from A to D giving an overall Performance rating for the Louvre.
Example
Aerodynamic Coefficient:
- Entry: 0.289
- Discharge: 0.284
Airflow Class:
- Entry: 3
- Discharge: 3
Rain Penetration Class:
- A up to 3.0m/s
Overall Performance Classification:
- A3 up to 3.0m/s
